Biology subjects

Allain, J.-M.

Publications and source records attributed to Allain, J.-M..

3 recordsLinked to original sources

bioRxiv2025

The Rapid Mechanically Activated (RMA) channel transduces increases in plasma membrane tension into transient calcium influx

O_LIPlants respond to mechanical stimuli by a rapid increase in cytosolic calcium. The intensity and kinetics of the calcium changes define calcium signatures important for biological responses . In this study, we determine the properties of a calcium permeable force-gated channel localized at the plasma membrane called Rapid Mechanically Activated (RMA). C_LIO_LIUsing patch-clamp and pressure-clamp, we characterized the kinetics of activation and inactivation of RMA channel upon stimulation by pulses of pressure applied onto the plasma membrane. Combining repetitive pressure pulse protocols at different frequencies with modeling, we investigated the channels capacity to transduce high frequency mechanical stimuli. C_LIO_LIRMA channel rapidly activates in response to membrane tension, then it inactivates during prolonged stimulation. Upon repeated stimulations, RMA current amplitude decreases irreversibly indicating that undergoes adaptation. The channel kinetics may be modeled with four chemical states and the model predicts that it behaves as a pass band filter in the 10 Hz - 1 kHz range. C_LIO_LIIn conclusion, due to its activation/inactivation characteristics, RMA channel is a candidate to mediate cytosolic calcium signaling in response to mechano-stimulation. Its adaptation and filtering properties suggest its involvement in the transduction of high frequency mechanical stimulation such as those produced by insects vibrations. C_LI

plant biology↗

bioRxiv2025

Community Challenge towards Consensus on Characterization of Biological Tissue: C4Bios First Findings

This study investigates methodological variability across various expert laboratories worldwide, with regards to characterizing the mechanical properties of biological tissues. Two testing rounds were conducted on the specific use case of uniaxial tensile testing of porcine aorta. In the first round, 24 labs were invited to apply their established methods to assess inter-laboratory variability. This revealed significant methodological diversity and associated variability in the stress-stretch results, underscoring the necessity for a standardized approach. In the second round, a consensus protocol was collaboratively developed and adopted by 19 labs in an attempt to minimize variability. This involved standardized sample preparation and uniformity in testing protocol, including the use of a common cutting and thickness measurement tool. Despite protocol harmonization, significant variability persisted across labs, which could not be solely attributed to inherent biological differences in tissue samples. These results illustrate the challenges in unifying testing methods across different research settings, underlining the necessity for further refinement of testing practices. Enhancing consistency in biomechanical experiments is pivotal when comparing results across studies, as well as when using the resulting material properties for in silico simulations in medical research.

bioengineering↗

bioRxiv2019

Transduction of mechanical cellular oscillation by the plasma-membrane mechanosensitive channel MSL10

Throughout their life, plants are submitted to recurrent cyclic mechanical loading due to wind. The resulting passive oscillation movements of stem and foliage is an important phenomenon for biological and ecological issues such as photosynthesis optimization 1-3 and thermal exchange 4. The induced motions at plant scale are well described and analyzed, with oscillations at typically 1 to 3 Hz in trees 5-10. However, the cellular perception and transduction of such recurring mechanical signals remains an open question. Multimeric protein complexes forming mechanosensitive (MS) channels embedded in the membrane provide an efficient system to rapidly convert mechanical tension into electrical signal 11. Here we show that the plasma membrane mechanosensitive channel MscS-LIKE 10 (MSL10) from the model plant Arabidopsis thaliana responds to pulsed membrane stretching with rapid activation and relaxation kinetics in the range of one second. Under sinusoidal membrane stretching MSL10 presents a greater activity than under static stimulation and behaves as a large bandpass oscillation \"follower\" without filtering the signal in the range of 0.3 to 3 Hz. With a localization in aerial organs naturally submitted to oscillations, our results suggest that the mechanosensitive channel MSL10 represents a molecular component of a universal system of oscillatory perception in plants.

plant biology↗